Based on the information provided, it appears that your build of the NETCDF library was not successful. You need to check the build logs for NETCDF to see if there were any errors. Since the libnetcdf.a library does not contain these entry points, something must have failed during the build.

The output of the command "nm ./libnetcdf.a | grep -i nf_get_vara_real" is still null.
I'm quite puzzled as I compiled NETCDF without error and installation of NETCDF is no problem. Why the libnetcdf.a library does not contain these entry points? Is the problem caused by option --disable-netcdf-4?
Thanks, Roger